One of the most frustrating things for endurance athletes to deal with is a winter weather. It’s tough maintain fitness given cold and shortdays, but to get sick on top of it is maddening.

When I wrote the story on Chronic Fatigue Syndrome, one thing that I learned from the research is that aerobic exercise builds the immune system, while long durations of high intensity exercise stresses the immune system.

I was never able to find what experts believe to be the threshold for how much is "too much intensity." Does 30 seconds of anaerobic work tear down the immune system? How about a minute? Is it cumulative? Does 5 minutes spread over an hour tip people over the threshold of tearing down the immune system?

In short, we don’t know for sure.

When I have an athlete that is recovering from a cold, but not quite well yet (some seven to 10 days after the onset of cold symptoms), one workout I will include is intervals right around lactate threshold power (LTP). If you are using power now, you know your training zones based on a time trial. If you don’t have a system now, you can reference the free download intensity document and chart used in my training plans to give you a place to start.

The workout

Warm up 10 minutes at Zone 1 to 2 intensity

Beginning at the 10-minute mark, do 10 x 1 minute at the prescribed power level. Take 4 minutes of easy spinning at Zone 1 to 2 intensity between each interval. Intensity levels for each interval are:

#1 and #2 = LTP minus 25 to 20 watts

#3 and #4 = LTP minus 20 to 15 watts

#6 through #10 = LTP minus 10 watts to plus 5 watts

For example, if your LTP is 200 watts, your intervals would go as follows:

#1 and #2 = 175 to 180 watts

#3 and #4 = 180 to 185 watts

#6 through #10 = 190 to 205 watts

I’ve found that this workout helps ease the athlete backinto higher levels of work, without being exhausting. I do adjust the intervals some, depending on the individual athlete. You may have to adjust the power levels some or reduce the number of intervals, but remember the main goal is to recover from the illness to 100-percent health.